When our eyes move during REM sleep, we’re gazing at things within the dream world our brains have created, in line with a recent study by researchers at UC San Francisco. The findings shed light not only into how we dream, but in addition into how our imaginations work.
REM sleep -; named for the rapid eye movements related to it -; has been known because the Fifties to be the phase of sleep when dreams occur. However the purpose of the attention movements has remained a matter of much mystery and debate.
“We showed that these eye movements aren’t random. They’re coordinated with what’s happening within the virtual dream world of the mouse,” said Massimo Scanziani, PhD, senior writer on the study, which appears within the Aug. 25, 2022, issue of Science.
This work gives us a glimpse into the continued cognitive processes within the sleeping brain and at the identical time solves a puzzle that is triggered the curiosity of scientists for a long time.”
Massimo Scanziani, PhD, senior writer on the study
Connecting eye movement with dream direction
Within the second half of the twentieth century, some experts hypothesized that these REM movements could also be following scenes within the dream world, but there was little solution to test it, and the experiments that could possibly be done (noting a dreamers’ eye direction after which waking them as much as ask where they were looking within the dream) provided contradictory results. Many researchers wrote off REM movements as random actions, perhaps to maintain the eyelids lubricated.
Given way more advanced technology, Scanziani, together with UCSF postdoctoral researcher Yuta Senzai, PhD, were able to have a look at “head direction” cells within the brains of mice, who also experience REM sleep. These cells act something like a compass, and their activity shows researchers which direction the mouse perceives itself as heading.
The team concurrently recorded data from these cells concerning the mouse’s heading directions while monitoring its eye movements. Comparing them, they found that the direction of eye movements and of the mouse’s internal compass were precisely aligned during REM sleep, just as they do when the mouse is awake and moving around.
A superbly harmonious fake world
Scanziani is interested by the “generative brain,” meaning the power to make up objects and scenarios.
“Considered one of our strengths as humans is that this capability to mix our real-world experiences with other things that do not exist at this time moment and should never exist,” he said. “This generative ability of our brain is the idea of our creativity.”
It’s difficult to check one of these brain function, nonetheless; it requires looking into the brain while it’s developing recent experiences and concepts within the absence sensory input. Dreaming provides just that chance.
In a dream, Scanziani noted, you possibly can mix familiar things with the unattainable. He described a recurrent dream he had as a young diver, wherein he was in a position to breathe under water. Invariably, he woke up to seek out it wasn’t true. “But within the dream, you suspect it’s real because there aren’t sensory inputs to bring you back to reality,” said Scanziani. “It’s a wonderfully harmonious fake world.”
Scanziani’s team found that the identical parts of the brain -; and there are various of them -; coordinate during each dreaming and wakefulness, lending credence to the concept that dreams are a way of integrating information gathered throughout the day.
How those brain regions work together to provide this generative ability is the mystery that Scanziani plans to proceed attempting to unravel.
“It is important to grasp how the brain updates itself based on amassed experiences,” he said. “Understanding the mechanisms that allow us to coordinate so many distinct parts of the brain during sleep will give us insight into how those experiences turn into a part of our individual models of what the world is and the way it really works.”
Source:
University of California – San Francisco